Why did Otto, the three patron saints in Diga Altman, become a stone statue?

You can learn about the background of Diga Altman. Diga Altman's setting is: 30 million years ago, an ultra-ancient civilization was born (even more developed than today's human beings), and Altman visited the earth at this time. However, due to the charm of Chikuris flowers, human beings are immersed in the illusion of rising and falling, rejecting the power of Altman. Altman will only protect human beings and will not interfere with human choices, so Dijia turned his body into a stone statue.

After 30 million years, 2 1 century, great changes began. At this time, earth defense force (TDF) completed its historical mission and was replaced by World Peace Organization (TPC). GUTS (Global Unlimited Mission, translated from Mandarin into Victory Team) received a hint from ancient times and found the stone statue of Diga Altman, and the story of Diga began.